1. Field of the Invention
This invention relates to fixtures or jigs for use in the factory precasting of concrete panels with built-in outer frames of sash windows or the like.
2. Prior Art
In the art of prefabrication of buildings it is desirable, for higher efficiency of construction, to precast concrete wall panels integral with the outer frames of sash windows or the like, rather than to install such outer frames in the walls of a building on the site. For the production of such precast concrete panels with built-in outer window frames or the like, it is customary to place the outer frame around and in contact with several abutments fixedly mounted in prescribed positions on a platform constituting the bottom of a form into which concrete is to be poured. A holder frame is then placed over the outer frame to force same down into close contact with the platform.
If, in the above described conventional fixture means, the outer frame is not forced into sufficiently close contact with the platform, the concrete poured into the form will intrude into the inside of the outer frame through a space between the platform and the bottom edge of the outer frame. Exertion of any undue downward forces on the outer frame, however, would cause the shelf or wall portions of the outer frame, which are arranged perpendicular to the platform, to buckle outwardly or inwardly depending upon the position of the holder frame relative to the outer frame and the cross sectional shape of the outer frame.